1. Field of the Invention
The present invention is directed to a method for controlling the operation of a printer carriage motor. More specifically, the present invention relates to a method for controlling the motor acceleration/deceleration and/or hold time for a printer carriage motor in a multiple print head printer based on all or any of the following: cartridge type, number of cartridges installed, weight of cartridges, number of print heads installed in the printer, etc.
2. Description of Related Art
Conventional ink jet printers have either a single print head or a multiple print head arrangement for printing. In the latter case, printing speed of image data is increased using the multiple print head design. For example, U.S. patent application Ser. No. 08/901,560, filed Jul. 28, 1997, entitled Auto-Alignment System For A Printing Device, discloses an example of a method which increases the print speed of serial image printing while using two print heads, one to print the left half of a printed line, and the other to print the right half of a printed line, both halves being printed simultaneously. To achieve this result, the left and right print head assemblies are supported by common carriage mechanism and are driven by a common printer carriage motor. As a result, print speed is approximately doubled over that of a single print head device.
Conventionally, in multiple print head printers, it is possible to install either one or two print heads, and print heads which include one or more ink cartridges. However, due to the difference in physical weight of each of the different types of print heads and cartridges, as well as the number of print heads being utilized by the multiple print head, accurate movement of the print head carriage cannot be obtained using a single speed motor due to the number and weight of the print heads installed. That is, because the printer carriage motor conventionally operates at a fixed speed in a multiple print head printer, if the number of print heads is changed, the speed may be either too much or too little to ensure proper printing speed. For example, if only one print head is used in a multi-head printer which has a fixed speed motor, the carriage speed would become too fast causing the print head either to overshoot its destination because too much power is supplied to the print head carriage or not provide sufficient time for the print head to eject ink at specific locations along a printable scan line due to the fast movement. Alternatively, if more than one print head is used in which each of the print heads includes more than one ink cartridge, the speed of the print head carriage may be reduced due to the increased weight and the lack of power supplied to the printer carriage motor for moving the heavier print heads. As may be appreciated, this problem is compounded when using two or more print heads which use more than two ink reservoirs.
In view of the varied weight and number of print heads which can be used in a multiple print head printer, it is desirable to maintain a constant known speed of the printer carriage in order to ensure proper printing quality. Therefore, the number of print heads as well as the weight of the print heads used must be known in order to control the speed of the printer carriage motor so as to ensure accurate movement of the print head carriage.